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dingusppc/devices/common/viacuda.h

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/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-22 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/** VIA-CUDA combo device emulation.
Versatile interface adapter (VIA) is an old I/O controller that can be found
in nearly every Macintosh computer. In the 68k era, VIA was used to control
various peripheral devices. In a Power Macintosh, its function is limited
to the I/O interface with the Cuda MCU. I therefore decided to put VIA
emulation code here.
Cuda MCU is a multipurpose IC built around a custom version of the Motorola
MC68HC05 microcontroller. It provides several functions including:
- Apple Desktop Bus (ADB) master
- I2C bus master
- Realtime clock (RTC)
- parameter RAM (first generation of the Power Macintosh)
- power management
MC68HC05 doesn't provide any dedicated hardware for serial communication
protocols. All signals required for ADB and I2C will be generated by Cuda
firmware using bit banging (https://en.wikipedia.org/wiki/Bit_banging).
*/
#ifndef VIACUDA_H
#define VIACUDA_H
#include <devices/common/adb/adb.h>
#include <devices/common/hwcomponent.h>
#include <devices/common/hwinterrupt.h>
#include <devices/common/i2c/i2c.h>
#include <devices/common/nvram.h>
#include <memory>
#define VIA_CLOCK_HZ 783360
/** VIA register offsets. */
enum {
VIA_B = 0x00, /* input/output register B */
VIA_A = 0x01, /* input/output register A */
VIA_DIRB = 0x02, /* direction B */
VIA_DIRA = 0x03, /* direction A */
VIA_T1CL = 0x04, /* low-order timer 1 counter */
VIA_T1CH = 0x05, /* high-order timer 1 counter */
VIA_T1LL = 0x06, /* low-order timer 1 latches */
VIA_T1LH = 0x07, /* high-order timer 1 latches */
VIA_T2CL = 0x08, /* low-order timer 2 latches */
VIA_T2CH = 0x09, /* high-order timer 2 counter */
VIA_SR = 0x0A, /* shift register */
VIA_ACR = 0x0B, /* auxiliary control register */
VIA_PCR = 0x0C, /* periheral control register */
VIA_IFR = 0x0D, /* interrupt flag register */
VIA_IER = 0x0E, /* interrupt enable register */
VIA_ANH = 0x0F, /* input/output register A, no handshake */
};
/** VIA interrupt flags */
enum {
VIA_IF_CA2 = 1 << 0,
VIA_IF_CA1 = 1 << 1,
VIA_IF_SR = 1 << 2,
VIA_IF_CB2 = 1 << 3,
VIA_IF_CB1 = 1 << 4,
VIA_IF_T2 = 1 << 5,
VIA_IF_T1 = 1 << 6
};
enum class ViaLine {
CA1,
CA2,
CB1,
CB2
};
/** Cuda communication signals. */
enum {
CUDA_TIP = 0x20, /* transaction in progress: 0 - true, 1 - false */
CUDA_BYTEACK = 0x10, /* byte acknowledge: 0 - true, 1 - false */
CUDA_TREQ = 0x08 /* Cuda requests transaction from host */
};
/** Cuda packet types. */
enum {
CUDA_PKT_ADB = 0,
CUDA_PKT_PSEUDO = 1,
CUDA_PKT_ERROR = 2,
CUDA_PKT_TICK = 3,
CUDA_PKT_POWER = 4
};
/** Cuda pseudo commands. */
enum {
CUDA_WARM_START = 0x00, /* warm start */
CUDA_START_STOP_AUTOPOLL = 0x01, /* start/stop device auto-polling */
CUDA_READ_MCU_MEM = 0x02, /* read internal Cuda memory */
CUDA_GET_REAL_TIME = 0x03, /* get real time */
CUDA_READ_PRAM = 0x07, /* read parameter RAM */
CUDA_WRITE_MCU_MEM = 0x08, /* write internal Cuda memory */
CUDA_SET_REAL_TIME = 0x09, /* set real time */
CUDA_POWER_DOWN = 0x0A, /* power down system */
CUDA_WRITE_PRAM = 0x0C, /* write parameter RAM */
CUDA_MONO_STABLE_RESET = 0x0D, /* mono stable reset */
CUDA_RESTART_SYSTEM = 0x11, /* restart system */
CUDA_FILE_SERVER_FLAG = 0x13, /* set file server flag */
CUDA_SET_AUTOPOLL_RATE = 0x14, /* set auto-polling rate */
CUDA_GET_AUTOPOLL_RATE = 0x16, /* get auto-polling rate */
CUDA_SET_DEVICE_LIST = 0x19, /* set device list */
CUDA_GET_DEVICE_LIST = 0x1A, /* get device list */
CUDA_ONE_SECOND_MODE = 0x1B, /* one second interrupt mode */
CUDA_READ_WRITE_I2C = 0x22, /* read/write I2C device */
CUDA_COMB_FMT_I2C = 0x25, /* combined format I2C transaction */
CUDA_OUT_PB0 = 0x26, /* output one bit to Cuda's PB0 line */
};
/** Cuda error codes. */
enum {
CUDA_ERR_BAD_PKT = 1, /* invalid packet type */
CUDA_ERR_BAD_CMD = 2, /* invalid pseudo command */
CUDA_ERR_BAD_SIZE = 3, /* invalid packet size */
CUDA_ERR_BAD_PAR = 4, /* invalid parameter */
CUDA_ERR_I2C = 5 /* invalid I2C data or no acknowledge */
};
#define CUDA_IN_BUF_SIZE 256
/** PRAM addresses within Cuda's internal memory */
#define CUDA_PRAM_START 0x100 // starting address of PRAM
#define CUDA_PRAM_END 0x1FF // last byte of PRAM
#define CUDA_ROM_START 0xF00 // starting address of ROM containing Cuda FW
/** Latest Cuda Firmware version. */
#define CUDA_FW_VERSION_MAJOR 0x0002
#define CUDA_FW_VERSION_MINOR 0x0029
class ViaCuda : public HWComponent, public I2CBus {
public:
ViaCuda();
~ViaCuda() = default;
static std::unique_ptr<HWComponent> create() {
return std::unique_ptr<ViaCuda>(new ViaCuda());
}
// HWComponent methods
int device_postinit();
uint8_t read(int reg);
void write(int reg, uint8_t value);
void assert_ctrl_line(ViaLine line);
#ifdef DEBUG_CPU_INT
void assert_int(uint8_t flags);
#endif
private:
// VIA virtual HW registers
uint8_t via_regs[16];
float via_clk_dur; // one VIA clock duration = 1,27655 us
// VIA internal state
uint32_t sr_timer_id = 0;
bool sr_timer_on = false;
// timer 1 state
bool t1_active;
uint16_t t1_counter;
uint32_t t1_timer_id = 0;
uint64_t t1_start_time = 0;
// timer 2 state
bool t2_active;
uint16_t t2_counter;
uint32_t t2_timer_id = 0;
uint64_t t2_start_time = 0;
// VIA interrupt related stuff
InterruptCtrl* int_ctrl;
uint32_t irq_id;
uint8_t _via_ifr;
uint8_t _via_ier;
uint8_t old_ifr = 0;
/* Cuda state. */
uint8_t old_tip;
uint8_t old_byteack;
uint8_t treq;
uint8_t in_buf[CUDA_IN_BUF_SIZE];
int32_t in_count;
uint8_t out_buf[16];
int32_t out_count;
int32_t out_pos;
uint8_t poll_rate;
int32_t real_time = 0;
bool file_server;
uint16_t device_mask = 0;
bool is_open_ended; // true if current transaction is open-ended
uint8_t curr_i2c_addr; // current I2C address
uint8_t cur_pram_addr; // current PRAM address, range 0...FF
void (ViaCuda::*out_handler)(void);
void (ViaCuda::*next_out_handler)(void);
std::unique_ptr<NVram> pram_obj;
std::unique_ptr<ADB_Bus> adb_bus;
// VIA methods
void print_enabled_ints(); // print enabled VIA interrupts and their sources
void init_ints();
void update_irq();
void assert_sr_int();
void assert_t1_int();
void assert_t2_int();
void schedule_sr_int(uint64_t timeout_ns);
uint16_t calc_counter_val(const uint16_t last_val, const uint64_t& last_time);
// CUDA methods
void cuda_init();
void write(uint8_t new_state);
void response_header(uint32_t pkt_type, uint32_t pkt_flag);
void error_response(uint32_t error);
void process_packet();
void process_adb_command(uint8_t cmd_byte, int data_count);
void pseudo_command(int cmd, int data_count);
void null_out_handler(void);
void pram_out_handler(void);
void out_buf_handler(void);
void i2c_handler(void);
/* I2C related methods */
void i2c_simple_transaction(uint8_t dev_addr, const uint8_t* in_buf, int in_bytes);
void i2c_comb_transaction(
uint8_t dev_addr, uint8_t sub_addr, uint8_t dev_addr1, const uint8_t* in_buf, int in_bytes);
};
#endif /* VIACUDA_H */
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